The present invention relates to a method and apparatus for determining a mixing regime for use in the preparation of animal feed from a set of ingredients, and the invention also relates to a system for use in the preparation of the animal feed.
Mixer/feeder apparatus, and in particular, mixer/feeder wagons for preparing a batch of animal feed from ingredients are well known. Such mixer/feeder wagons may be of the type commonly referred to as paddle mixer/feeder wagons, auger type mixer/feeder wagons and tub type mixer/feeder wagons. A paddle type mixer/feeder wagon is disclosed in PCT Published Application Specification No. WO 96/32836 of the present applicant and British Patent Specification No. 2,139,911. Typically, such mixer/feeder wagons comprise a mixing compartment in which the ingredients are homogenously mixed, and a dispensing compartment from which the mixed ingredients are dispensed. A mixing rotor, which typically is a paddle mixer, is rotatably located in the mixing compartment for mixing the ingredients of the animal feed therein. The mixer/feeder wagon disclosed in PCT published Application Specification No. WO 96/32836 comprises chopping blades located in the lower portion of the mixing compartment which co-operate with mixing paddles of the mixing rotor as the mixing rotor rotates for chopping ingredients which require chopping, and in particular for chopping fibrous ingredients into desirable lengths.
Auger type mixer/feeder wagons are disclosed in U.S. Pat. Nos. 4,951,883 and 5,622,323. Such auger type mixer/feeder wagons comprise a mixing compartment within which one or more longitudinally extending mixing augers are located. The mixing augers urge the animal feed in forward and rearward directions within the mixing compartment in order to mix the animal feed therein.
Tub type mixer/feeder wagons, in general, comprise a single vertically oriented mixing auger located in a mixing compartment which urges the animal feed upwardly through the mixing compartment, which then falls downwardly, to be urged upwardly again by the vertically oriented mixing auger, and so the mixing of the animal feed continues.
Typically, the animal feed comprises fibrous ingredients, such as, for example, long or short cut silage, hay, straw, maize, maize silage, wheat, oats, soda grain and/or sugar beet. Other ingredients of such animal feeds include additives and concentrates, for example, mineral additives and concentrates, energy additives and concentrates and liquids.
It has been found that the selection of the types of ingredients of a batch of animal feed, and in particular, the selection of the proportions of the ingredients which make up the animal feed is important in order to obtain optimum yields, such as milk output or weight gain from animals fed with the animal feed. It has also been found that the duration of a mixing cycle to which animal feed is subjected in a mixer/feeder wagon or other mixer/feeder apparatus is also important in producing an animal feed to produce optimum yields from animals fed with the animal feed. In particular, it is important to avoid both over-mixing and under-mixing of animal feed. Under-mixing results in the ingredients not being homogenously mixed, and thus, animals can subsequently pick and choose the more tasty ingredients of the animal feed, thus leaving the less tasty ingredients behind. Over-mixing can result in deterioration of the nutritional value of the animal feed, and in particular can result in deterioration of the fibrous material, and its properties of stimulating digestion of the nutrients in the animal feed in the animal's stomach. This is particularly so in the case of ruminants, such as beef cattle and milking and dry cows. In mixer/feeder wagons which include a chopping facility, such as the mixer/feeder wagon disclosed in PCT published Application Specification No. WO 96/32836, whereby the ingredients of the animal feed are simultaneously subjected to chopping and mixing, over-mixing of ingredients and in particular over-mixing of the fibrous ingredients can also lead to over-chopping of such ingredients. Over-chopping of the fibrous ingredients can result in the fibrous ingredients in the mixed animal feed being of lengths which are too short to stimulate optimum digestion of the nutrients in the animal's stomach. Over-mixing can also result in deterioration of the fibrous ingredients to the extent that the property of the fibrous material to enhance the digestive function of the stomach is lost. Under-mixing of fibrous material in such mixer/feeder wagons which also simultaneously chop the ingredients as well as producing an animal feed which is inadequately mixed also results in some of the fibrous material of the animal feed being of excessive lengths and sizes.
Accordingly, it is important that a mixing regime to which ingredients of an animal feed is subjected should be such as to avoid over-mixing of the ingredients and also under-mixing of the ingredients.
The present invention is directed towards a method and apparatus for determining a mixing regime for use in the preparation of animal feed from a set of ingredients which addresses the problem of over-mixing and under-mixing of ingredients of an animal feed. The invention is also directed towards a system for producing an animal feed which addresses the problem of over-mixing and under-mixing of ingredients.